16 Matching Results

Search Results

Advanced search parameters have been applied.
in creator/contributor: "CHOQUETTE,KENT D."  
Results: 1 - 16
open access

Selective Oxidation Technology and its Applications Toward Electronic and Optoelectronic Devices

Description: Selective oxidation of AlGaAs compounds has facilitated dramatic improvements in the performance of near IR VCSELS. Under the auspices of this proposal we have: (1) expanded our understanding of both the strengths and the limitations of this technology; (2) explored its applicability to other Al bearing materials; (3) utilized this technology base to demonstrate a variety of new electronic and optoelectronic devices; and (4) established the reliability and manufacturability of oxidized devices … more
Date: July 1, 1999
Creator: Spahn, Olga B.; Allerman, Andrew A.; Choquette, Kent D.; Vawter, Gregory A.; Klem, John F.; Sullivan, Charles T. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Advanced Concepts for High-Power VCSELS and 2-Dimensional VCSEL Arrays

Description: We have developed high power vertical cavity surface emitting lasers (VCSELS) for multimode or single mode operation. We have characterized new cavity designs for individual lasers and 2-dimensional VCSEL arrays to maximize output power. Using broad area high power VCSELS under pulsed excitation, we have demonstrated the triggering of a photoconductive semiconductor switch (PCSS) with a VCSEL. We also have developed designs for high output power in a single mode. The first approach is to engine… more
Date: April 1, 1999
Creator: Allerman, A. A.; Choquette, Kent D.; Chow, W. W.; Geib, K. M.; Hadley, R.; Hou, H. Q. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Bistable Output from a Coupled-Resonator Vertical-Cavity Laser Diode

Description: The authors report a monolithic coupled-resonator vertical-cavity laser with an ion-implanted top cavity and a selectively oxidized bottom cavity which exhibits bistable behavior in the light output versus injection current. Large bistability regions over current ranges as wide as 18 mA have been observed with on/off contrast ratios of greater than 20 dB. The position and width of the bistability region can be varied by changing the bias to the top cavity. Switching between on and off states ca… more
Date: July 20, 2000
Creator: Fischer, Arthur J.; Choquette, Kent D.; Chow, Weng W.; Allerman, Andrew A. & Geib, Kent M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Single transverse mode selectively oxidized vertical cavity lasers

Description: Vertical cavity surface emitting laser (VCSEL) sources have been adopted into Gigabit Ethernet applications in a remarkably short time period. VCSELs are particularly suitable for multimode optical fiber local area networks (LANs), due to their reduced threshold current, circular output beam, and inexpensive and high volume manufacture. Moreover, selectively oxidized VCSELs are nearly ideal LAN sources since the oxide aperture within the laser cavity produces strong electrical and optical confi… more
Date: April 18, 2000
Creator: CHOQUETTE,KENT D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Q-Switched Operation of a Coupled-Resonator Vertical-Cavity Laser Diode

Description: The authors report Q-switched operation from an electrically-injected monolithic coupled-resonator structure which consists of an active cavity with InGaAs quantum wells optically coupled to a passive cavity. The passive cavity contains a bulk GaAs region which is reverse-biased to provide variable absorption at the lasing wavelength of 990 nm. Cavity coupling is utilized to effect large changes in output intensity with only very small changes in passive cavity absorption. The device is shown t… more
Date: February 8, 2000
Creator: Fischer, Arthur J.; Chow, Weng W.; Choquette, Kent D.; Allerman, Andrew A. & Geib, Kent M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Room Temperature Continuous Wave InGaSsN Quantum Well Vertical Cavity Lasers Emitting at 1.3 um

Description: Selectively oxidized vertical cavity lasers emitting at 1294 nm using InGaAsN quantum wells are reported for the first time which operate continuous wave at and above room temperature. The lasers employ two n-type Al{sub 0.94}Ga{sub 0.06}As/GaAs distributed Bragg reflectors each with a selectively oxidized current aperture adjacent to the optical cavity, and the top output mirror contains a tunnel junction to inject holes into the active region. Continuous wave single mode lasing is observed up… more
Date: June 5, 2000
Creator: Choquette, Kent D.; Klem, John F.; Fischer, Arthur J.; Spahn, Olga B.; Allerman, Andrew A.; Fritz, Ian J. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Comparison of Fabrication Approaches for Selectively Oxidized VCSEL Arrays

Description: The impressive performance improvements of laterally oxidized VCSELs come at the expense of increased fabrication complexity for 2-dimensional arrays. Since the epitaxial layers to be wet-thermally oxidized must be exposed, non-planarity can be an issue. This is particularly important in that electrical contact to both the anode and cathode of the diode must be brought out to a package. They have investigated four fabrication sequences suitable for the fabrication of 2-dimensional VCSEL arrays.… more
Date: April 18, 2000
Creator: Geib, Kent M.; Choquette, Kent D.; Allerman, Andrew A.; Briggs, Ronald D. & Hindi, Jana Jo
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

GaAsSb/InGaAs type-II quantum wells for long-wavelength lasers on GaAs substrates

Description: The authors have investigated the properties of GaAsSb/InGaAs type-II bilayer quantum well structures grown by molecule beam epitaxy for use in long-wavelength lasers on GaAs substrates. Structures with layer, strains and thicknesses designed to be thermodynamically stable against dislocation formation exhibit room-temperature photoluminescence at wavelengths as long as 1.43 {mu}m. The photoluminescence emission wavelength is significantly affected by growth temperature and the sequence of laye… more
Date: March 15, 2000
Creator: Klem, John F.; Spahn, Olga B.; Kurtz, Steven R.; Fritz, Ian J. & Choquette, Kent D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Effective Index Model Predicts Modal Frequencies of Vertical-Cavity Lasers

Description: Previously, an effective index optical model was introduced for the analysis of lateral waveguiding effects in vertical-cavity surface-emitting lasers. The authors show that the resultant transverse equation is almost identical to the one typically obtained in the analysis of dielectric waveguide problems, such as a step-index optical fiber. The solution to the transverse equation yields the lateral dependence of the optical field and, as is recognized in this paper, the discrete frequencies of… more
Date: April 18, 2000
Creator: Serkland, Darwin K.; Hadley, G. Ronald; Choquette, Kent D.; Geib, Kent M. & Allerman, Andrew A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Single Transverse Mode Selectively Oxidized Vertical Cavity Lasers

Description: Vertical cavity surface emitting lasers (VCSELs) which operate in multiple transverse optical modes have been rapidly adopted into present data communication applications which rely on multi-mode optical fiber. However, operation only in the fundamental mode is required for free space interconnects and numerous other emerging VCSEL applications. Two device design strategies for obtaining single mode lasing in VCSELs based on mode selective loss or mode selective gain are reviewed and compared. … more
Date: April 26, 2000
Creator: Choquette, Kent D.; Geib, Kent M.; Briggs, Ronald D.; Allerman, Andrew A. & Hindi, Jana Jo
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Composite Resonator Surface Emitting Lasers

Description: The authors have developed electrically-injected coupled-resonator vertical-cavity lasers and have studied their novel properties. These monolithically grown coupled-cavity structures have been fabricated with either one active and one passive cavity or with two active cavities. All devices use a selectively oxidized current aperture in the lower cavity, while a proton implant was used in the active-active structures to confine current in the top active cavity. They have demonstrated optical mo… more
Date: May 1, 2000
Creator: Fischer, Arthur J.; Choquette, Kent D.; Chow, Weng W.; Allerman, Andrew A. & Geib, Kent M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Two-Element Phased Array of Anti-Guided Vertical-Cavity Lasers

Description: We demonstrate for the first time anti-guided coupling of two adjacent vertical-cavity surface-emitting lasers (VCSEL's), obtaining a 1-by-2 phase-locked array at 869 nm. The lateral index modification required for anti-guiding is achieved by a patterned 3-rim etch performed between two epitaxial growths. In contrast with prior evanescently coupled VCSEL's, adjacent anti-guided VCSEL's can emit in-phase and produce a single on-axis lobe in the far field. Greater than 2 mW of in-phase output pow… more
Date: September 27, 1999
Creator: Allerman, Andrew A.; Choquette, Kent D.; Geib, Kent M.; Hadley, G. Ronald & Serkland, Darwin K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Near-Field Spectroscopy of Selectively Oxidized Vertical Cavity Surface Emitting Lasers

Description: Selectively oxidized vertical cavity surface emitting lasers (VCSELS) have been studied by spectrally resolved near field scanning optical microscopy (NSOM). We have obtained spatially and spectrally resolved images of both subthreshold emission and lasing emission from a selectively oxidized VCSEL operating at a wavelength of 850 nm. Below threshold, highly local high gain regions, emitting local intensity maxima within the active area, were observed; these were found to serve as lasing center… more
Date: December 9, 1999
Creator: Kim, J.; Boyd, J. T.; Jackson, Howard E. & Choquette, Kent D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Coupled Resonator Vertical Cavity Laser Diode

Description: We report the operation of an electrically injected monolithic coupled resonator vertical cavity laser which consists of an active cavity containing In{sub x}Ga{sub 1{minus}x}As quantum wells optically coupled to a passive GaAs cavity. This device demonstrates novel modulation characteristics arising from dynamic changes in the coupling between the active and passive cavities. A composite mode theory is used to model the output modulation of the coupled resonator vertical cavity laser. It is sh… more
Date: September 16, 1999
Creator: CHOQUETTE, KENT D.; CHOW, WENG W.; FISCHER, ARTHUR J.; GEIB, KENT M. & HOU, HONG Q.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen